The present invention relates to a golf club head made of a fiber-reinforced resin, and more particularly, to such a golf club head in which the edges of the scoring lines or punch marks on the face are hardly damaged when a ball is hit with the golf club.
At least the outermost layer of the face of a golf club head made of a fiber-reinforced resin is usually reinforced with a reinforcing cloth material in order to increase the breaking strength of the face when it is used for hitting a ball. The face has grooves parallel to one another which are called `scoring lines`. The scoring lines are formed by cutting after molding or by molding monolithically with the golf club head. However, when the scoring lines of the golf club head made of the fiber-reinforced resin are formed by the former cutting method, the reinforcing cloth material in the outermost layer is cut to cause delamination. Therefore, the latter molding method in which the scoring lines are formed when the golf club head is molded is preferred in the production of the golf club head made of the fiber-reinforced resin. However, this method also has problems.
Namely, since the reinforcing cloth material has a high rigidity, it is impossible to form it so as to be faithfully fitted along the crossectional shape of the grooves of the scoring lines. A part of the edges of the scoring lines becomes composed of only the matrix resin. In other words, as shown in a crossection of FIG. 4, a relatively large part of the molding of the matrix resin not reinforced with a reinforcing cloth 26 is formed in an edge 27 of a scoring line 24. Therefore, the edge 27 is apt to be broken by an impact applied thereto when a ball is hit. This problem is posed also when punch marks, in the form of holes, are formed in addition to the scoring lines.